Transformer installation



June 26, 1923. 1,459,988

w. A. PRESSEY TRANSFORMER INSTALLATI ON Filed A112. 25 1919 FTgJ.

l2 ao u a7- 33 10 l6 26 as I; 24 I2 22 I ll Inventor:

Wi Hour A. Presse y,

Patented June 26, 1923.

UNITED STATES 1,459,988 PATENT OFFICE.

WILBUR A. PRESSEY, F PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TRANSFORMER INSTALLATION.

Application filed August 25, 1819. Serial No. 819,70a.

To all whom it may concern.-

Be it known that I, WILBUR A. PRESSEY,

a citizen of the United States, residin at Pittsfield, in the county of Berkshire, btate of Massachusetts, have invented certain new and useful Improvements in Transformer Installations, of which the following is a specification.

My invention relates to transformer installations, and has for its general ob'ect an improved arrangement of parts w ereby transformers and like electrical apparatus ma be safely, cheaply and economically insta led.

A specific object of my invention is to provide an arrangement whereby the socalled transformer houses, customarily built to enclose and protect transformers which are installed on the exterior of the buildings to be supplied with from, may be dispensed with.

A further specific ob'ect of my invention isto decrease the fire azards which occur in conjunction with the installing of transformers in the neighborhood of buildings.

In accomplishing these objects I make use of an improved construction of the cover and tank containing the transformer which permits the use of conductors enclosed in 30 grounded conduits for supplying energy to and from the transformer; the tank proper being so constructed that breathing (due to the normal expansion and contraction of the oil as it becomes alternately heated and cooled with the variation of the load on the transformer) can take place Without liability of the oil overflowing onto the exterior of the tank by reason of undue expansion of the oil such as would result if a fire occurred in the neighborhood of the tank.

For a more complete understanding of the nature and objects of my invention reference should be had to the following detailed description, taken in connection with the accompanying drawings in which:

Fig. 1 shows in side elevation, a transformer installation embodying my invention. Fig. 2 is an enlarged fragmentary View, partly in section, showing details in the tank construction employed in the practice of my invention.

Referring now to Fig. 1, A denotes a tower, or other convenient support for the electric mains C from which it is desired to supply alternating current electric energy to power therethe building B, where such energy is to be consumed.

A transformer having a tank or casing D is placed in the electrical connections leading to the building B, and is employed to effect the desired ratio between the line yoltage of the mains C and that of the service buses, shown at E, in the building B. This transformer is located on the exterior of building B and in accordance with my invention the customary housing structure, protecting fence, or the like, is dispensed with; thus materially reducing the cost of installation where my invention is employed.

In order to properly protect the electrical connections, Where no housing structure is employed, the cover 10 of the tank D is provided with one or more auxiliary casings or compartments, two being shown in Fig. 2, as at 11 and 12, in which the connections to the transformer are made andhoused. The compartment 11 is arranged to house the line connections and .contains the line bushings 13 leading to the transformer in the tank D, such bushings having their upper ends specifically designed for service in such compartments. From the upper end of the bushings 13, electrical connections are made, s by conductors 14, to the end-bell 15 on the armored-cable 16; which cable may be led underground, as shown at 17, to a suitable pot-head 18 into which are led the taps 19 from the electric mains C. The bell at 15 is conveniently anchored in a depending portion 20 of the compartment 11, which compartment is preferably provided with a removable weather tight top or lid as shown at 21 in order to give ready access to the electrical connections, and is also preferably made detachable from the cover, the bolts 22 being shown to indicate this function, but it will be understood by those skilled in the art that any convenient way of securing such compartment to the cover may be employed.

The compartment 12 is similar to compartment 11, and houses the service bushings 23, which are electrically connected byconductors 24 to the cable 26; the latter being also shown as led underground to connect with service buses E.

On the interior of the tank D, the bushings 13 and 23 are provided respectively with ground sleeves 30 and 30 which terminate with thickened ends 31 and 31 sub- These ground sleeves serve in the well known manner to relieve the electro-static strains in the air-space above the oil in the tank D.

Communicating with the air-space above the oil level is a standard breather 33 comprising a tubular passage to the atmosphere from this air-space provided with a chamber containing some dehydrating substance, as calcium chloride. To prevent the oil from escaping from the tank through this breather, in case the oillevel undul from any cause, I provid the tank with the overflow connection t5 which leads to a seweror other convenient place of discharge.

The overflow connection has a mouth 36 open to the interior of the tank D slightly above the maximum allowable oil level, and also has a trap 37 to normally close communication between the air-space in the tank D and the place of discharge. The trap may be of any convenient form, that shown being provided with a check valve. The trap may likewise be located at any convenient point in the connection 35; a location lower than that shown frequently being desirable in order to provide a greater head of oil to open the check valve. The use of such trap insures the proper functioning of the breather, and at the same time provides for the free egress of the oil from the tank D to a safe polnt of discharge in case of undue expansion of the oil.

As will be seen by the use of my invention there is no exposed electric wiring, all exposed parts being at ground potential; which permits outdoor transformers to be safely installed in the neighborhood of buildings.

My improved tank, in which all excess of oil that rises abovethe maximum allowable oil level is syphoned away to a safe place of discharge, insures that in case of fire, there will be no external overflow of oil to increase "rose the hazard, nor will there be live electrical parts exposed so as to endanger the lives of firemen when playing the hose on the fire, if it should be in the neighborhood of the transformer installation.

The leading of the cables to connect into depending portions of the compartments l1 and 12 or superstructure on the tank permits the transformer and its tank to be readily removed without interfering with installation of the cables themselves.

While I have here shown an embodiment of my invention which is at present the best means known to me for carrying the same into effect, I would have it understood that this is merely illustrative and that I do not mean to be limited thereby to the precise details here disclosed since obvious alterations thereof will appear to those skilled in this art, nor in the choice of recognized equivalents except as defined in my claim hereunto annexed.

What I claim as new and desire to secure by Letters Patent is In a transformer installation, an outdoor high tension transformer enclosed in a grounded metal casing, metal connection compartments extending outwardly from said casing and having depending portions at their outer ends, conductors from underground to the high tension side of said transformer, other conductors from underground to the low tension side of said transformer, said conductors passing through openings in the depending portions of said connection compartments and being provided with connections within said compartments, and grounded metal protection enclosing the conductors between the ground and said compartments. i

In witness whereof, I have hereunto set my hand this twenty-first day of August 1919.

'WILBUR A. PRESSEY. 

